Palestinian Authority Foreign Minister Nasser Al-Kidwa said Thursday that Israel's withdrawal from the Gaza Strip could lead to peace or could obstruct a final settlement and a pullout from the West Bank. In a tough speech to the UN General Assembly, Al-Kidwa expressed pessimism about Israel's intentions in the West Bank. He demanded an immediate halt to the expansion of settlements and construction of the separation barrier, which he said is destroying the livelihood of tens of thousands of Palestinians. While Al-Kidwa recognized that the Israeli withdrawal from Gaza was an important development, he accused Israel of leaving the strip "completely devastated" and called its occupation of Gaza "one of the worst injustices in recent history." Israeli Prime Minister Ariel Sharon has reaped diplomatic rewards for ending the country's 38-year Gaza occupation. In the past two weeks, Qatar, Pakistan and Indonesia have held high-level public meetings with Israel - a rare event for Muslim countries - and Sharon met Friday with Jordan's King Abdullah II for their first talks in months. Al-Kidwa accused Israel and some of its friends of trying to undermine an eventual Palestinian state and evading UN resolutions. He urged Israel to stop trying to "market these policies and positions in the United Nations and in other international forums." "This will be the start of the solution and the start of the final, peaceful and permanent settlement, which must be based on law, legitimacy and United Nations resolutions," he said. The Palestinians are prepared to return to negotiations and to start quickly implementing the road map peace plan drafted by the so-called Quartet - the United States, the United Nations, the European Union and Russia, he said. Al-Kidwa also reiterated Palestinian leader Mahmoud Abbas' readiness "to begin final status negotiations immediately." But in addition to halting settlement activities and construction of the barrier, he said, there must be quick solutions to outstanding issues in Gaza. They include the Rafah crossing into Egypt, the airport, the seaport, the removal of rubble and the link between the West Bank and the Gaza Strip. Al-Kidwa said the Palestinians recognized that the withdrawal from Gaza required "political boldness," but stressed that the government would be watching to see what Israel does next. "All of this will determine whether the disengagement will take us further steps forward, closer to a comprehensive settlement and peace - or whether it is actually a step imposed by the realities on the ground and intended to facilitate the continuation of the occupation ... of the West Bank, and to obstruct a final settlement," he said. Al-Kidwa stressed that Israel's continuing control over Gaza's borders and airspace are evidence that its occupation has not ended - and he warned that without a permanent link to the West Bank and freedom of moment the densely populated strip cannot survive economically or politically. "What Israel is doing in the West Bank, particularly in East Jerusalem, is cause for us to be even more pessimistic," he said, citing continuing construction of the barrier in violation of a ruling by the International Court of Justice and a General Assembly resolution. In his speech Thursday to the UN summit, Sharon said the Palestinians are entitled to their own state and his country has no desire to rule them. He urged reconciliation and compromise with Palestinians to end their conflict. But he said that after Israel's Gaza withdrawal, it was up to the Palestinians to "prove their desire for peace" by halting terror and disarming militants. Al-Kidwa said the Palestinians "will continue to exert efforts to impose law and order" and to build democracy, including holding elections at all levels "Israel must stop its attempts to interfere in and sabotage these elections," he said. The Palestinians have also worked seriously "to get out of the cycle of military attacks and counterattacks" and the general atmosphere has improved, Al-Kidwa said. "It is incumbent upon both sides to develop it."